Do you have 'custom firmware' on your 3DS or just homebrew? You will need custom firmware to install a .cia (It's not a file that you can load up with only homebrew), if you have not updated to the latest version of the 3DS (11.4) and are on 11.2, you can get custom firmware through Luma3DS. There is an entire guide on that. TL;DR: You don't put it in the 3ds folder because you have to install the .cia file through FBI which needs custom firmware.
no u.u i use homebrew, im in the version 11.3.0.36 and all time i have this green screen when i try open jksm, sorry im new in this.